By Robert Jacobson and Casey Hickcox
The presence of pallid sturgeon (Scaphirhynchus albus) on the Federal Endangered Species List generally boils down to their inability to reproduce in the wild. Scientists suspect shallow-water habitat lost when the Missouri River was re-engineered in the mid-19th to mid-20th century to be a contributing factor in this loss of natural recruitment. Understanding the dynamics of the hydrology, hydraulics, and habitats in those shallow environments is critical for informed restoration, but working in the shallow depths can be quite challenging.
High water throughout June and early July offered research boats extended access to shallow water habitat restoration areas on the Lower Missouri River. Over several weeks, CSRP scientists documented water depths and velocities in the Lisbon and Jameson chutes near Arrow Rock, Missouri (approximately 1.9 and 2.8 miles long, respectively)along with approximately 8.5 miles of the adjacent mainstem channel. By establishing transects perpendicular to the mainstem river at 50 meter intervals and in the chutes at 20 meters, researchers used an acoustic Doppler current profiler (ADCP) to measure water velocities while an Odom survey-grade single-beam echosounder recorded river bathymetry at a resolution that will support two-dimensional hydrodynamic models of the river-chute complex (see Figure 2). These models are intended to be used to gain a better understanding of the environments available to sturgeon larvae and juveniles, including the potential for drifting free embryos to be intercepted and retained in the chutes.